| Climate types | Humidity index (Iu) |
| A → super humid | Iu ≥ 100 |
| B4 →humid | 80 ≤Iu < 100 |
| B3 → humid | 60 ≤Iu < 80 |
| B2 → humid 40 ≤ Iu < 60 | 40 ≤Iu < 60 |
| B1 → humid 20 ≤ Iu < 40 | 20 ≤ Iu < 40 |
| C2 → semi-humid 0 ≤ Iu < 20 | 0 ≤ Iu < 20 |
| C1 → dry semi-humid −20 ≤ Iu < 0 | −20 ≤ Iu < 0 |
| D → semi-arid −40 ≤ Iu < −20 | −40 ≤ Iu < −20 |
| E → arid −60 ≤ Iu < −40 | −60 ≤ Iu < −40 |